Progress 10/01/12 to 09/30/17
Outputs
Target Audience:General biology, cancer biology, disease prevention and stem cell biology audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate and graduate students are working on these projects. How have the results been disseminated to communities of interest?Publications in peer reviewed journals What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Ras signaling originates from transient nanoscale compartmentalized regions of the plasma membrane composed of specific proteins and lipids. The highly specific lipid composition of these nanodomains, termed nanoclusters, facilitates effector recruitment and therefore influences signal transduction. This suggests that Ras nanocluster proteolipid composition could represent a novel target for future chemoprevention interventions. There is evidence that consumption of fish oil containing long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) such as eicosapentaenoic acid (EPA, 20:5D5,8,11,14,17) and docosahexaenoic acid (DHA, 22:6D4,7,10,13,16,19) may reduce colon cancer risk in humans, yet the mechanism underlying this effect is unknown. Here, we demonstrate that dietary n-3 PUFA reduce the lateral segregation of cholesterol-dependent and -independent nanoclusters, suppressing phosphatidic acid-dependent oncogenic KRas effector interactions, via their physical incorporation into plasma membrane phospholipids. This results in attenuation of oncogenic Ras-driven colonic hyperproliferation in both Drosophila and murine models. These findings demonstrate the unique properties of dietary n-3 PUFA in the shaping of Ras nanoscale proteolipid complexes and support the emerging role of plasma membrane-targeted therapies. Significance: The influence of dietary long chain n-3 polyunsaturated fatty acids on plasma membrane protein nanoscale organization and KRas signaling supports development of plasma membrane-targeted therapies in colon cancer.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2018
Citation:
N.R. Fuentes, M. Mlih, R. Barhoumi, P. Hardin, T. Steele, S. Behmer, I. Prior, J. Karpac and R.S. Chapkin. Long chain n-3 fatty acids attenuate oncogenic Ras-driven proliferation by altering plasma membrane nanoscale proteolipid composition. Cancer Research 78:3899-3912, 2018. PMID:29769200; PMCID:PMC6050089
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
A. Erazo-Oliveras, N.R. Fuentes, R.C. Wright and R.S. Chapkin. Functional link between plasma membrane spatiotemporal dynamics, cancer biology and membrane altering agents. Cancer & Metastasis Reviews 37:519-544, 2018. PMID:29860560
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:General biology, cancer biology, disease prevention and stem cell biology audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate and graduate students are working on these projects. How have the results been disseminated to communities of interest?Publications in peer reviewed journals What do you plan to do during the next reporting period to accomplish the goals?Further probe the dose-related effects of n-3 PUFA on plasma membrane structure / function across cell types.
Impacts
What was accomplished under these goals?
Cell membrane fatty acids influence fundamental properties of the plasma membrane, including membrane fluidity, protein functionality, and lipid raft signaling. Evidence suggests that dietary n-3 polyunsaturated fatty acids (PUFA) may target the plasma membrane of immune cells by altering plasma membrane lipid dynamics, thereby regulating the attenuation of immune cell activation and suppression of inflammation. Since lipid-based immunotherapy might be a promising new clinical strategy for the treatment of inflammatory disorders, we conducted in vitro and in vivo experiments to examine the effects of n-3 PUFA on CD4+ T cell membrane order, mitochondrial bioenergetics and lymphoproliferation. n-3 PUFA were incorporated into human primary CD4+ T cells phospholipids in vitro in a dose-dependent manner, resulting in a reduction in whole cell membrane order, oxidative phosphorylation and proliferation. At higher doses, n-3 PUFA induced unique phase separation in T cell-derived giant plasma membrane vesicles (GPMVs). Similarly, in a short-term human pilot study, supplementation of fish oil (4 g n-3 PUFA/d) for 6 wks in healthy subjects significantly elevated eicosapentaenoic acid (C20:5n3) levels in CD4+ T cell membrane phospholipids, and reduced membrane lipid order. These results demonstrate that the dynamic reshaping of human CD4+ T cell plasma membrane organization by n-3 PUFA may modulate down-stream clonal expansion.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
134. C. Whitfield-Cargile, N. Cohen, K. He, I. Ivanov, J. Goldsby, A. Chamoun-Emanuelli, B. Weeks, L.A. Davidson and R.S. Chapkin. The non-invasive exfoliated transcriptome (exfoliome) reflects the tissue-level transcriptome in a mouse model of NSAID-enteropathy. Nature Scientific Reports 7:14687, 2017. PMID:29089621
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
135. Y.Y. Fan, N.R. Fuentes, T.Y. Hou, R. Barhoumi, X.C. Li, N.E. Deutz, M.P. Engelen, D.N. McMurray and R.S. Chapkin. Remodeling of primary human CD4+ T cell plasma membrane order by n-3 polyunsaturated fatty acids. British Journal of Nutrition (In Press).
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Progress 10/01/15 to 09/30/16
Outputs
Target Audience:General biology, cancer biology, disease prevention and stem cell biology audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate and graduate students are working on these projects. How have the results been disseminated to communities of interest?Publications in peer reviewed journals What do you plan to do during the next reporting period to accomplish the goals?Continue to work with the newly developed preclinical models to elucidate molecular mechanisms of action. Also, have submitted an NIH translational grant where fish oil and a high fiber diet will be tested in a clinical trial.
Impacts
What was accomplished under these goals?
Bioactive dietary molecules such as n-3 polyunsaturated fatty acids (PUFA), curcumin, and fermentable fiber have been proposed to exert chemoprotective effects, and their molecular mechanisms have been the focus of research in the dietary/chemoprevention field. Using these bioactives as examples, we have investigated the mechanisms by which they exert their effects, from the nucleus to the cellular membrane. In addition, emerging technologies involving the culturing of colonic organoids to study physiological effects of dietary bioactives is also being utilized. We have also addressed future challenges to the field regarding the identification of additional molecular mechanisms and other bioactive dietary molecules that can be utilized in our fight to reduce the incidence of colorectal cancer. Since numerous bioactive compounds found in the intestinal lumen can directly interact with lipid membranes, we hypothesize that the dynamic reshaping of plasma membrane organization underlies the chemoprotective effect of select membrane targeted dietary bioactives (MTDBs).
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2016
Citation:
1. E. Kim, L.A. Davidson, R.S. Zoh, M.E. Hensel, M.L. Salinas, B.S. Patil, G.K. Jayaprakasha, E.S. Callaway, C.D. Allred, N.D. Turner, B. Weeks and R.S. Chapkin. Rapidly cycling Lgr5+ stem cells are exquisitely sensitive to extrinsic dietary factors that modulate colon cancer risk. Cell Death & Disease 7:e2460, 2016. PMID:27831561
- Type:
Journal Articles
Status:
Accepted
Year Published:
2016
Citation:
Y.Y. Fan, E. Callaway, J.M. Monk, P. Yang, L. Vincent and R.S. Chapkin. A new model to study the role of arachidonic acid in colon cancer pathophysiology. Cancer Prevention Research 9:750-757, 2016. PMID:27339171 PMCID:PMC5010973
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Progress 10/01/14 to 09/30/15
Outputs
Target Audience:General biology, cancer biology, disease prevention, and stem cell biology audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Undergraduate and graduate students are working on these projects. How have the results been disseminated to communities of interest?Publications in peer reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Continue to work with the newly developed preclinical models to elucidate molecular mechanisms of action. Also, have submitted an NIH translational grant where fish oil and a high fiber diet will be tested in a clinical trial.
Impacts
What was accomplished under these goals?
Projects in this research area are designed to assess how the chemoprotective properties of dietary lipid are altered when a highly fermentable fiber, pectin, rather than a poorly fermentable fiber, cellulose, is added to the diet. This protective effect is mediated in part by the up-regulation of targeted apoptosis of DNA adducts during tumor initiation. Our findings indicate that highly fermentable fiber, which generates butyrate in the colon, only has chemotherapeutic value when n-3 PUFA is the lipid source. With respect to a molecular mechanism of action, n-3 PUFA and butyrate (a microbial fermentation product), in combination, synergistically induce a novel p53-independent, oxidation-sensitive, mitochondrial Ca2+-dependent (intrinsic) pathway. This critical observation emphasizes the need to examine both the lipid and fiber composition of diets. The lab is now focusing on the impact of gut-related metabolites onintestinal stem cell biologyin vivo and ex vivo using acolonic organoid model system.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
Hou, T.Y., Barhoumi, R., Fan, Y.Y., Rivera, G.M., Hannoush, R.N., McMurray, D.N., and Chapkin, R.S. (2015) n-3 polyunsaturated fatty acids uniquely alter phosphatidylinositol-(4,5)-bisphosphate (PIP2) organization which precedes suppression of the CD4+ T cell proliferative response. Biochimica et Biophysica Biomembranes 1858:85-96
- Type:
Journal Articles
Status:
Accepted
Year Published:
2015
Citation:
DeClercq, V., McMurrary, D.N., and Chapkin, R.S. (2015) Obesity promotes colonic stem cell expansion during cancer initiation. Cancer Letters 369:336-343
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: General biology, cancer biology, disease prevention, and stem cell biology audiences. Changes/Problems: Funding is a challenge. What opportunities for training and professional development has the project provided? Serveral laboratory personnel refined the model system to grow intestinal crypts in vivo. How have the results been disseminated to communities of interest? Not yet. What do you plan to do during the next reporting period to accomplish the goals? Continue to use the in vitro model to further examine the effect of nutritional bioactives on stem cell biology.
Impacts
What was accomplished under these goals?
Outputs: Arachidonic acid (20:4?5,8,11,14, AA)-derived prostaglandin E2 (PGE2 ) promotes colon cancer development. In contrast, chemoprotective n-3 polyunsaturated fatty acids (PUFA) supplant AA, thereby decreasing PGE2 biosynthesis in colonocytes, with eicosapentaenoic acid (20:5?5,8,11,14,17, EPA) in particular being metabolized to a novel 3-series E-prostaglandin (PGE3 ), a putative anti-tumorigenic-cyclooxygenase metabolite. Since transformation of adult stem cells is an extremely important route towards initiating intestinal cancer, we utilized the Lgr5-EGFP-IRES-creERT2 knock-in mouse model to isolate and culture colonic organoids, in order to document ex vivo responses to exogenous 2 and 3-series prostaglandins. Colonic crypts were isolated from transgenic mice and cultured in a Matrigel based 3-D platform. Organoids were treated with exogenous PGE2 , PGE3 or DMSO (vehicle control) for 5 days and the number of viable organoids was recorded daily. Subsequently, samples were processed for immunohistochemistry, flow cytometry and real time PCR analyses. PGE2 promoted optimal organoid growth and induced significantly higher levels of cell proliferation (P < 0.05) compared to PGE3 and control. In contrast, the Lgr5-GFP positive stem cell number was uniquely elevated by > 2-fold in PGE2 treated cultures compared to PGE3 and control. This coincided with the up-regulation of stem cell related Sox9, Axin2, and Cd44 mRNAs. Our results demonstrate that relative to AA-derived PGE2 , a known promoter of colon tumorigenesis, EPA-derived PGE3 has diminished ability to support colonic stem cell expansion in mouse colonic organoids. Outcomes: Using a recently described three-dimensional culture system, we were able to monitor the growth of mouse colonic crypts, stem cell self-renewal and differentiation in vitro. This in vitro organoid culture model fully recapitulates the Wnt- and Notchdependent intestinal stem cell niche. We provide evidence that chemoprotective EPA-derived PGE3 has diminished ability to support colonic stem cell expansion in mouse colonic organoids as compared to AA-derived PGE2. Future studies will focus on the combinatorial effects of PGE2/PGE3 on stem cell biology. We propose that the enablement of primary intestinal organoid culture will have widespread application for elucidating the molecular mechanisms of nutrient action on gut biology.
Publications
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: General biology, cancer biology, disease prevention, and stem cell biology audiences. Changes/Problems: Funding is a challenge. What opportunities for training and professional development has the project provided? Serveral laboratory personnel refined the model system to grow intestinal crypts in vivo. How have the results been disseminated to communities of interest? Not yet. The paper will be published shortly. What do you plan to do during the next reporting period to accomplish the goals? Continue to use the in vitro model to further examine the effect of nutritional bioactives on stem cell biology.
Impacts
What was accomplished under these goals?
Outputs: Arachidonic acid (20:4?5,8,11,14, AA)-derived prostaglandin E2 (PGE2) promotes colon cancer development. In contrast, chemoprotective n-3 polyunsaturated fatty acids (PUFA) supplant AA, thereby decreasing PGE2 biosynthesis in colonocytes, with eicosapentaenoic acid (20:5?5,8,11,14,17, EPA) in particular being metabolized to a novel 3-series E-prostaglandin (PGE3), a putative anti-tumorigenic-cyclooxygenase metabolite. Since transformation of adult stem cells is an extremely important route towards initiating intestinal cancer, we utilized the Lgr5-EGFP-IRES-creERT2 knock-in mouse model to isolate and culture colonic organoids, in order to document ex vivo responses to exogenous 2 and 3-series prostaglandins. Colonic crypts were isolated from transgenic mice and cultured in a Matrigel based 3-D platform. Organoids were treated with exogenous PGE2, PGE3 or DMSO (vehicle control) for 5 days and the number of viable organoids was recorded daily. Subsequently, samples were processed for immunohistochemistry, flow cytometry and real time PCR analyses. PGE2 promoted optimal organoid growth and induced significantly higher levels of cell proliferation (P < 0.05) compared to PGE3 and control. In contrast, the Lgr5-GFP positive stem cell number was uniquely elevated by > 2-fold in PGE2 treated cultures compared to PGE3 and control. This coincided with the up-regulation of stem cell related Sox9, Axin2, and Cd44 mRNAs. Our results demonstrate that relative to AA-derived PGE2, a known promoter of colon tumorigenesis, EPA-derived PGE3 has diminished ability to support colonic stem cell expansion in mouse colonic organoids. Outcomes: Using a recently described three-dimensional culture system, we were able to monitor the growth of mouse colonic crypts, stem cell self-renewal and differentiation in vitro. This in vitro organoid culture model fully recapitulates the Wnt- and Notch-dependent intestinal stem cell niche. We provide evidence that chemoprotective EPA-derived PGE3 has diminished ability to support colonic stem cell expansion in mouse colonic organoids as compared to AA-derived PGE2. Future studies will focus on the combinatorial effects of PGE2/PGE3 on stem cell biology. We propose that the enablement of primary intestinal organoid culture will have widespread application for elucidating the molecular mechanisms of nutrient action on gut biology.
Publications
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Replaces project TEX03039 PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Nothing to report
Publications
- No publications reported this period
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